1. Field of the Invention
The present invention relates to an X-ray analyzer which detects X-rays secondarily generated from a sample when X-rays are irradiated onto the sample and measures the metal concentrations in the sample.
2. Description of the Related Art
Traditionally, in the case where metal concentrations in a plastic are measured by an X-ray analyzer, when the type of this plastic is unknown, the metal concentrations are analyzed assuming that a typical plastic creates a calibration curve, where the horizontal axis is X-ray intensity and the vertical axis is metal concentrations. When a plastic discriminating device utilizing near-infrared rays and infrared rays can be used, metal concentrations in plastics are analyzed by a method in which information of polyvinyl chloride and polyethylene that are outputted from the plastic discriminating device are used to create calibration curves according to the types of plastics. As a method for determining types of plastics with near-infrared rays, a method is proposed in which near-infrared rays are irradiated onto a plastic product, the absorbance is measured in the range of 1000 to 2500 nm at pitches of a wavelength of six nanometers (hereinafter, it is expressed by ‘nm’), differential values are calculated at individual measurement points and are separated into plus, zero or minus to know the characteristics of the absorbance, this plus/0/minus is compared with the data of plus/0/minus at each of known plastics measured beforehand, and the type of plastic is determined by the relevance factors between them (for example, see Patent Reference 1).
[Patent Reference 1] JP-A-6-308022 (PP. 3 to 4)